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Oxygen sensor

Question : I bought a vehicle with the oxygen sensor only having 2 lead heads, and it does not have any extra wire or 'lead head' available for the purpose of illuminating the Malfunction Indicator Light (MIL).

The design of the oxygen sensor is such that it does not signal the ECU to trigger the MIL to illuminate. Is such a design standard practice by all car manufacturers?

The oxygen sensor is already obsolete from what I know because most vehicles now are using heated 4 lead head.

Without the engine system alert, how does the owner know that the O2 sensor is faulty or when the O2 sensor was out of specs like burnt, over-contaminated or even opened/shorted circuit?

Without this warning light and if the oxygen sensor is faulty, it will become the single greatest source of excessive emission, and I have to pay more for fuel consumption. An overly rich fuel mixture will also damage the vehicle's catalytic converter.

Answer : You know what you are talking about. However, every manufacturer designs its vehicle in its own particular way.

It does not mean that the O2 sensor in your vehicle has only 2 leads, that the wrong component has been fitted. If the O2 sensor is malfunctioning and the indicator light is not coming on, you should get the service people to get that rectified. It may be a harness or even an ECU problem, which only they with their test equipment would be in the best position to identify. In the first place you will need to confirm that the sensor is actually malfunctioning and to do so would mean having access to the service and test data of the manufacturer. I agree that a faulty O2 sensor can result in poor fuel consumption, high emissions, etc. and I am sure the vehicle manufacturer would be fully aware of this just by putting the vehicle on the emissions test rig and connecting up the ECU tester.

After having worked most of my life with a major vehicle manufacturer, I can say for a fact that if a defect is found, they will leave no stones unturned until a solution is found and all the problem vehicles rectified.

In this modern age, no one in his right mind can sweep any technical problem under the carpet, so to speak, because at the stroke of a keyboard, the whole world can be made aware of the problem, with incalculable damage to reputations. Please update us if you have a problem with the rectification.


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